come to (one's) senses
To start thinking reasonably. I'm glad she finally came to her senses and decided against those hideous bridesmaids' dresses. Don't worry, Paul will come to his senses and agree to the terms of the contract.
come to one's senses
Return to thinking or behaving sensibly and reasonably; recover consciousness. For example, I wish he'd come to his senses and stop playing around. This term employs senses in the sense of "normal or sane mental faculties," and in the earliest recorded use (1637) it meant "recover from a swoon." Its broader present-day meaning dates from the mid-1800s. The related bring someone to his or her senses was used by John Gay in his Beggars' Opera (1727). Also see take leave (of one's senses).